Antenna



Jan. 8, 1952 R. s. BAILEY 2,581,348

ANTENNA Filed April 10, 1948 2 SHEETS-SHEET l ELE CLFOMA H VE GNET 6 'C 9 10 11 4 l l A l ,0f/Asn? gft/Xl I2/ Y Cf 7 7n Cl/ 3) cncpe le lo Y m f /YBQ Jan. 8, 1952 R. s. BAILEY 2,581,348

ANTENNA 2 SHEETS-SHEET 2 Filed April l0, 1948 A TTfP/VEY Patented Jan. 8, 1952 o UNITED STATES PAT ENT 'FFICE Y AAN'JEEMNA Roberts. Bailey, New YorlgiN.. Y: as$lgnongt International'Standai-d Electric Corporation, New York, rlp-312,11.A corporation of Delaware Applicatloaaprn; 1o, 194s; serial Ng-.;..2'0:3 2g

IWBDQB .relates to antennas.' endinore -"Fig.''1vshows 'the inventi/omas embodiediinf-an .particularly it relates to antennas for c fcient Vwlenti-:rima ,arrayzof the; reiicctor=directorkind. Snerati@:n .at veryhi'gh ,freguencies over abroad Fig-.'Bi-showsf;anfantennafarray accordingtothe hand! Vinvnation,rand.especially1*designed:for broad lfre-- Aplinpalpbjeot of the "invention 'is to proil; Aquencyfband'x'eceygxtion of horizontally polarized vide an antenna system which lmore'eilig:iently waves.

Yutilts the mglleticcomponent of the radiation ,'Fi'gri'fzzshowsfhowthe-magnetic characteristics field. of.;an;antenna:1 according to: .the-invention, can be l,Another,object is to provide a receiving antenna -signaifcontrolled.solastcvaryits frequency sensi- .Whrein the `pickup element is constituted of af-101 "ivflfV Gharactestiii@ magnetic member of predetermined permeability iFig. lofshowsithe invention -as embodied in a V.and permittivity per-unit length, and .is electro- :lobesrvitch-mg;system.,

magnetically coupled to a radio receiver or the Thepresentinyention is based primarily on the like. fiactetha rrod,-zpreerabiyecylindrical in cross .AILQIhcr object is ,to provide more efficienti; section, and: .composedrptcompacted finelycomvantenna array lfor broad frequency band'foperf-minutedi .magnetic-Lparticlesnhas. a -eweturns of ation. y :wire .Wound around the.,;central ;region it --acts further object is to provide a novel combinavmoreseimziently with spent to` very high -fretion Akof antenna elements., one elementresponding .ritieni-:yL 4wiwexvz.'than: clo s `the conventional *non- .Eoiently to the electric component of the vradi-90` rmagnetic' or ijeleQlTiCfan-tenl1- F01 eXample,

ation eld, and another element respondingereferring t0 Fig. 1, there is shown a cylindrical ciently to the magnetic component of the 'vleld. 'rrod .ipconeposedf of :compacted and cemented A'feature of the invention relates'to a commagneticfpoyvderfsuch:asisconventionally used posite antenna array having elements which A/infhigli'frequencyftnning; Vslugs and the like. respond efficiently to magnetic components, and .23' Wound naifonrid :the .fentxal 'flegOn Of the IOd,

non-magnetic elements which-respond efciently arezzaturnsoff-wire which can-be'connected.

:larly'suitable for the reception of -very high or to electric components of a radiation eld. to anytsutablefradio Ireceiver 3. Y The arrow 4 .Another feature relates to an array of magnetic represents -anarriving wave having electric and antenna units and a cooperating array of electric magnetic ',ctgmnfitments. The electric component antenna units, which are mutually disposed Vto fsobeingrepreend by lhearlow'. and` the mag- Yprovide an overall characteristic of precise direc- :netic .'or-Affmfgzllctostatic- .component being Arepretivity and broad frequency band response. '.'sentedby-the..arrow-6. Irllhesexamrows, in accord- Another' feature relates to an antenna vcomfence Ninthv Well-known -letlfmagnetc -WaVe prised of va group of magnetic antennav units theory. aT-emuiully DBrpendGlllal' t0 each Other. Whose respective magnetic permeabilities are prey35` Preferablyralihllgh nQUneSSar-ly, the rOd l iS determined and chosen of different values cor- .'disposedeso :as :to .be.;paral1el. .to vthe magnetic related with-respective predetermined irequenfcomponentHof--thefarriving wave. It can be cies sothat the Vantenna has an overall v,characshown-motif@DY'gYen-Ygon 0f Spa@ Where teristic: of precise directivity and broad frequency the-rod "il-'iis located, the ratio of magnetic ux ibandresponse. e gth to thegilin; inthe cylindrical A further-feature relates to an improvedbroad cr Szetollal :radius a `^and Vfrequency band antenna array which isparticud pelpfmii'fvty Kain a -ultra high frequencies.

vThealcove-mentioned and otherfeatues-and 5 3 N ,.4 Ii -zfT-lfw/KM) objects of this invention and the manner -of f2 .-eieo (1) attaining them will become more V apparent and Mr@ Kn ifilnz+fu2 the invention itself will be best understood, by

refe-renee to lthe following description of -an whereinpgeds'tlieglagioi-fthcilux inthe rod,behind embodiment of the inventionltaken in r`conjunction with the accompanying drawings, wherein:

m -theH of the incidentwave; a, and,

A the invention.

:magnetic and electric antenna according to the Fig. 1 is ageneralizeddiagram explanatory of .f t" J fr j" 1K1.;` La W Fig. 2 is a series of graphs also explanatory-of the invention. 5:,

Fig. '3 is a schematic diagram of acomposite v invention. l

Figs. e, 5 and 6 arerespectlve modifications for y Eig. 3 ce and tan ee=f/go; and Ji and Ni are the Bessel and Neuman functions. Also, the E. M. F. per

turn N of wire around the rodfis I v 21r Y u--NI whereas the E. M. F. produced in the conventional non-magnetic or electric antenna is ee=2a.

Therefore the efficiency or ratio ofthe two types of antennas is tivity K, and presents a higher voltage output em.,

than the output ee of a similar electric antenna. The ratio em/ee may reach a value of as much as to 15 for particular combinationsof p., K, N, i.

The present invention' also proposes to provide a magnetic antenna comprised of an array forz example of spaced units each consisting of a magnetic rod, the rods having different magnetic permeabilities, but with their permeabilities grouped around a center or mean permeability ne which coincides with the optimum ratio of"`V em/ee for the particular )t which is used. Since each antenna unit will have an E. M. F. gain of 10 to 15, or approximately 20 db, the net gain of such an array will be high, while-at the same time providing a broad frequency band char-1 acteristic.

Since the E. M. F. from an electric antenna parallel to the electric vector is ee=21.a, the

present invention also proposes an array consisting of crossed electric and magnetic antenna units. Such an array isvshown in Fig. 3 and comprises a vertically disposed cylindrical rod 1 of the above described compacted magnetic powder, and around the central region of which is wound a few turns of a coupling coil 8 elec-f trically insulated or spaced from rod 1. The terminals of coil 8 are connected to the input of any well-known phase 'adjuster 9', the output of which is connected by conductor I0 to a suitable radio receiver II. The other conductor I2 from phaser 9 is connected'tov the' receiver in circuit with an electric antennaIS, for example of the dipole kind, which is mounted preferably perpendicular to the rod 1. The radius as of antenna I3 is so designed,r andthe phaser 9 is also so adjusted, th'at'the E.4 M. ee from the electric antenna is in'additive'pha'se with respect tothe E. M. F. em from the magnetic antenna.

While Fig. 3 shows the two antennasl mutually perpendicular and with the electric antenna adv If desired, more than one magnetic antennaV unit can be employed. For example, there -is shown in Fig. 5 a two-element array comprising a pair of aligned magnetic antenna units I4, I5,

withV theirfrespective central coupling coils I6,A

l1. Mounted in crossed relation to unit I4 is an electric dipole I8, and a similar electric dipole I9 is mounted in crossed relation with unit I1. The several antenna units are connected, Yas shown, through a phase adjuster 20, and thence by transmission line 2i to a suitable radio receiver 22.

Fig. 6 shows an alternative array comprising a pair of magnetic antenna units 23, 24, with their respective coupling coils 25, 2B. Mounted in crossed relation to the units 23, 24, and on opposite sides thereof. are two arrays 21, 28, of electric dipoles, each array consisting of three dipoles connected in cross-feed relation as shown, to the transmission line 29. Suitable phase adjusters 30, 3l, 32, are provided between the magnetic units and the electric units so as to bring them into additive phase for application to the radio receiver.

Fig. 7 shows the invention embodied in an array of the Yagi kind. Such an antenna comprises the main dipole element 33, with the parasitic reector element 34, and a plurality of director elements 35, 36, 31, 38, all of which are supported from the common pole 39. As is known in this kind of antenna, the rod 39 may be a metal tube or rod to which the reector 34 and the directors 35-38 are also welded in parallel array. However, since the main element 33 is center driven, and is mechanically supDOrted from rod 39, it is electrically insulated so as to permit it to be connected to the transmission line 4D. Mounted in crossed relation to the unit 33 is a magnetic antenna unit 4I of compacted powdered magnetic material as above described, and having wound around its central region, but electrically insulated from rod 4I, the coupling coil 42 which is connected to line 40, through phaser 43, to bring the respective E. M. Fs em and fe into additive phase for application to the receiver 44. Also supported on rod 39 in symmetrical crossed relation with respect to each of the elements 34, 35, 36, 31, 38, are respective magnetic rods 45, 46, 41, 48, 49, similar to rod 4I.

The invention is not limited to the combination of electric and magnetic antenna units. For example, advantage may be taken of the frequency selective response of the magnetic unit,

to provide an array which is particularly eicient in connection with ultra high frequency horizontally polarized waves. Such an arrangement is shown in Fig. 8 and consists for example, of three rods 50, 5|, 52, of compacted powdered magnetic material, with their respective coupling coils 53, 54, 55, which are connected to the transmission line 56 so as to be in additive phase. If desired, suitable phase adjusters 51, 58, can be used to insure that the signals from the respective coils are brought into additive phase. As pointed out hereinabove, the magnetic rod antenna has a certain critical frequency response, depending upon its magnetic permeability and permittivity. Therefore, the antenna units 50, 5I, 52, are each designed with respective magnetic permeablities and permittivities, so that each unit is selectively efficient in an optimum manner to a diierent frequency. For'example, the unit 50 can be designed for a wave length k2: the unit 5I for a wave length kl; and the unit 52 for a wave length A3, and preferably so that ?\1-}\2=A3- \2. It will be 'understood of course. that while Fig. 8 shows an array of three magnetic antenna units, a greater number may be employed. In any such array it is preferred that one unit will be designed for optimum response at what may be termed a center wave length.

and the remaining units will be designed in pairs symmetrically disposed with relation to the center unit, but with each pair having an optimum response at a frequency equally spaced from the center frequency, and from the adjacent pair.

If desired, a single magnetic antenna unit can be employed and it can be connected to a suitable D. C. source so as to control its magnetic permeability. Thus as shown in Fig. 9, the magnetic rod 59 is provided with a coupling coil 60 for coupling the antenna to a radio set 6l which may be a radio transmitter or a radio receiver. Also wound around the antenna 59 is another coil 62 suitably insulated therefrom. Coil 62 is connected to a source 53 of adjustable direct current whereby the magnetic permeability of rod 59 can be adjusted so as to vary its optimum response for different frequency of impinging waves. If desired, the source r63 may be of the type which produces a saw-tooth wave of D. C. potential so as to cause the permeability of rod 59 to be varied progressively at a predetermined rate between two limits, thus likewise adjusting its optimum response with frequency. For example, source 63 may produce a D. C. wave which sweeps at a supersonic rate.

The arrangement of Fig. 9 can also be used to effect well-known lobe switching such as is employed in radar systems, guided landing systems and the like. Thus, as shown in Fig. 10, there may be provided an array of three antennas S4, 65, 66, which are excited and spaced to produce a predetermined directive radiation lobe, and the two side antennas can be keyed to cause the lobe to be moved to the right and left of a predetermined line. For a detailed description of such an antenna array, reference may be had to U. S. Patent No. 2,208,921 However, instead of employing three electric antennas as in said Patent No. 2,208,921 and keying the two side antennas on and oi, the present invention uses for the side antennas 65, 66, magnetic rods such as described hereinabove, and each of these rods is provided with its respective coupling coil 61, 68, each of which is connected to a source of D. C. potential to control its magnetic permeability. By keying these D. C. sources at a predetermined rate, there results a switching of the resultant radiation lobe from one side to the other of the center line, as schematically repre` sented in Fig. 10.

In all the foregoing embodiments the magnetic rod antenna should have a length approximately equal to one-half the wave length or a multiple thereof of the arriving waves.

While I have described above the principles of my invention in connection with specific apparatus, it is to be clearly understood that this description is made only by way of example and not as a limitation to the scope of my invention.

What is claimed is:

1. A composite antenna for very high frequency electromagnetic waves, comprising an antenna unit in the form of a rod of compacted powdered magnetic material which is selectively responsive to the magnetic components of an arriving electromagnetic wave, said rod being mounted parallel to the magnetic component of said wave, a non-magnetic antenna unit which is selectively responsive to the electric components of said wave, said non-magnetic unit being mounted parallel to the electric component of said wave, and phasing means to combine the responses of both said antenna units in additive phase.

2. An antenna according to claim l in which said magnetic unit is formed of a compacted powdered magnetic material having its magnetic permeability predetermined to produce an optimum response at the frequency of said wave.

3. An antenna according to claim 1 in which said magnetic unit has a coupling coil surrounding its central region and connected through a phase adjuster to a wave transmission line which connects with both units.

4. An antenna array comprising a plurality of rod-like magnetic antenna units each composed of compacted powdered magnetic material and mounted in linear alignment, and a plurality of non-magnetic antenna units symmetrically mounted with respect to the magnetic antenna units laterally disposed on either side of said magnetic units, iirst coupling means interconnecting the magnetic antenna units, second coupling means interconnecting the electric antenna units, and phasing means intercoupling said first and second coupling means in additive phase to a Wave transmission line.

5. An antenna particularly suitable for radio reception, comprising an elongated rod of compacted magnetic powder having a permeability chosen so as to have optimum response at a selected frequency of electromagnetic waves incident thereon, a coupling coil surrounding the central region of said rod, a dipole mounted in perpendicularly intersecting relation with the said central region and having the arms of the dipole extending laterally on opposite sides of said rod, and phasing means to combine the responses of the said rod and said dipole.

6. An antenna array comprising a main antenna, section consisting of an antenna unit in the form of a rod of compacted powdered magnetic material which is selectively responsive to an arriving electromagnetic wave. said rod being mounted parallel to the magnetic component of said wave, a non-magnetic antenna unit which is selectively responsive to the electronic components of said wave, said non-magnetic unit being mounted parallel to the electric component of said wave, and phasing means to combine the responses of both antenna units in additive phase, a parasitic reiiector section mounted rearwardly of said main section and at least one director antenna section mounted in advance of said main antenna section, each of said parasitic and director sections consisting of a crossed electric antenna element and of a magnetic antenna element which latter is composed of compacted powdered magnetic material.

ROBERT S. BAILEY.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,020,032 Fessenden Mar. 12, 1912 1,710,085 Cooper Apr. 23, 1929 2,266,262 Polydoroff Dec. 16, 1941 2,297,466 Funke et al Sept. 29, 1942 2,380,519 Green July 31, 1945 2,419,538 Clark Apr. 29, 1947 FOREIGN PATENTS Number Country Date 165,038 Great Britain Aug. 10, 1922 217,245 Great Britain Dec. 7. 1925 

